webpack.config.js

"use strict";
const NodePolyfillPlugin = require("node-polyfill-webpack-plugin");

/** @type {import("webpack").Configuration} */
module.exports = {
    mode: "none",
    entry: {
        eslint: ["core-js/stable", "regenerator-runtime/runtime", "./lib/linter/linter.js"]
    },
    output: {
        filename: "[name].js",
        library: "[name]",
        libraryTarget: "umd",
        globalObject: "this"
    },
    module: {
        rules: [
            {
                test: /\.m?js$/u,
                loader: "babel-loader",
                options: {
                    presets: [
                        ["@babel/preset-env", {
                            debug: true, // ← to print actual browser versions

                            /*
                             * We want to remove `transform-unicode-regex` convert because of https://github.com/eslint/eslint/pull/12662.
                             *
                             * With `>0.5%`, `@babel/preset-env@7.7.6` prints below:
                             *
                             *     transform-unicode-regex { "chrome":"49", "ie":"11", "safari":"5.1" }
                             *
                             * So this excludes those versions:
                             *
                             * - IE 11
                             * - Chrome 49 (2016; the last version on Windows XP)
                             * - Safari 5.1 (2011-2013; the last version on Windows)
                             */
                            targets: ">0.5%, not chrome 49, not ie 11, not safari 5.1"
                        }]
                    ]
                }
            }
        ]
    },
    plugins: [
        new NodePolyfillPlugin()
    ],
    resolve: {
        mainFields: ["browser", "main", "module"]
    },
    stats: "errors-only"
};